Several bifunctionally reactive linkers containing halide or sulfonate ester groups were prepared. The linkers were used to quaternize 5‐(4‐methoxyphenyl)‐2‐(4‐pyridyl)oxazole and 2‐(6‐chromanyl)‐5‐(4‐pyridyl)oxazole to produce fluorescent stains that contained a reactive group such as an isothiocyanate, an N‐hydroxysuccinimidyl ester, a maleimide, or an oxirane. The stains were derivatized with either 1‐propylamine, 1‐propanethiol, or piperidine, as appropriate, to help in characterization. The stains may serve as more photostable alternatives to fluoresceins or coumarins.